Two Washington ballot initiatives with nationwide ramifications, legalization of same-sex marriage and legalizing and regulating marijuana sales, have growing leads and are likely to pass next Tuesday, according to the latest Washington Poll.

The poll of 722 registered -- and 632 likely -- voters shows President Obama with an expanding lead in the Evergreen State, and Democrat Jay Inslee with a wafer-thin 48.7-45.6 percent lead over Republican Rob McKenna in the contest for Governor.

Referendum 74, which would bring marriage equality to Washington, is ahead 57.9-36.9 percent among likely voters. With a factoring in of those not willing to give a "socially undesirable" answer, the poll gives the adjusted prediction of a 52.3-45.8 perent victory margin among likely voters.

"We have seen no decrease in support for Referendum 74," said University of Washington political scientist Matt Barreto, overseer of the survey. The Washington Poll is a project of the UW and KCTS-TV.

Matt Initiative 502, which would legalize and tax the sale and cultivation of small amounts of marijuana, leads by 55.4-37.6 percent among likely voters.

The poll found that 33.4 percent of those surveyed have already mailed in their ballots, with early voters trending slightly Democratic.

If Referendum 74 is approved, Washington would be the seventh state in the nation to legalize same-sex marriage: 32 states have previously rejected marriage equality at the ballot box. Washington may be joined by Maryland and/or Maine. Both states are voting on marriage equality.

The Washington Poll has spent four years tracking changing attitudes of Evergreen State voters toward gay rights and same-sex unions. It found last fall that 55 percent of those surveyed would vote to uphold marriage equality if the Legislature passed it and the governor signed it.

The latest poll reflects trends seen across the country: 70.5 percent of voters under 30 support marriage equality, with only 21.8 percent opposed. The Baby Boomer generation, ages 45 to 65, backs it by a 55-39 percent margin.

Opposition exceeds 40 percent among those 65 and older: Only Republicans and Tea Party supporters are overwhelmingly opposed to marriage equality.

The governor's race is very, very close. While only 5.8 percent of those surveyed declared themselves undecided, "There could be as much as 17 percent of people who are moving around," as Barreto put it.

The poll tells why all those TV spots are filling your screen.

A total of 41.9 percent of likely voters say they are "certain" Inslee supporters, with 41.0 percent "certain" to vote for McKenna. But 4.4 percent say they are in the Inslee camp but "could change" with 2.4 percent "leaning" Inslee: 3.6 percent of McKenna voters "could change" with 1 percent as McKenna leaners.

The Washington Poll took up the attorney general's race: A $2.996 million outlay of cash from a Republican "SuperPAC" -- the Republican State Leadership Committee -- has brought Republican Reagan Dunn back after an abysmal primary showing.

Dunn trailed Democrat Rob McKenna by 13 points in the August primary. But the GOP group has flayed Ferguson in negative TV spots of questionable accuracy.

Has it worked? According to the Washington Poll, Ferguson is ahead by 44.9-34.0 percent among likely voters. Still, "certain" support for the Democratic King County Councilman is at only 36.6 percent of likely voters. It is 29.4 percent for Dunn. A whopping 21.1 percent say they are still undecided.

The "Cascade Curtain" rears its head repeatedly in the poll.

President Obama has a 62.6-31.1 percent lead over Mitt Romney in the Puget Sound region. But Romney is ahead 48.8-42.7 percent in Eastern Washington. Inslee tops McKenna 53.9-41.5 percent in the Puget Sound area, while McKenna is far ahead, 56.6-30.6 percent, in Eastern Washington even though Inslee once represented a district east of the Cascades in Congress.

The poll sampled other ballot issues.

Tim Eyman's Initiative 1185 has picked up opposition, but still leads 52.0-36.8 percent. It would require two-thirds "Supermajorities" in both houses of the Legislature to raise taxes or close corporate loopholes. Opponents of the measure have spent virtually no money. Major oil companies and the Beer Institute, fearful of paying fees or losing tax breaks, have underwritten Eyman.

Initiative 1240, the "billionaires initiative," has gained ground: It would legalize up to 40 Charter Schools in the state. It is ahead 55.5 percent to 37.5 percent."We've seen a very very significant increase in the Yes vote," said Barreto.

The initiative's TV campaign has been powered by the likes of Bill Gates, Paul Allen, Nick Hanauer, Steve Ballmer, the parents of Amazon.com founder Jeff Bezos and Alice Walton of the Wal-Mart family.